An environment-friendly leather waste-based liquid film mulching and its application for facilitating the growth of maize crops

Currently, environment-friendly high water-absorbing, water-retention, water-resistant, and water erosion resistance materials are the research hotspot in agricultural film. In this research, a new type of leather waste-based liquid film mulching (WG) was prepared by waterborne polyurethane (WPU) grafted with gelatin(G) extracted from leather waste. The interacting behavior of the prepared WG with soil particles was characterized including soil particles morphological changes, water-retention, water-resistant, water erosion resistance, and farming experiments. The SEM revealed that the WG could form a “coating layer” on the soil surface. The coating layer could improve the water-retention and water resistance of the soil. Meanwhile, the farming applications found that the soil sprayed WG could form a certain closed space which played a role in water-resistant, water erosion resistance, heat preservation, and moisture retention for maize. Especially, the water-absorbing, water-retention, and thermal-retention efficiency reached 80.5%, 20.2%, and 23.1 °C, respectively when the WG content was 50 g/m2 in the soil experimental sample. Moreover, after the WG was sprayed evenly on farmland, the germination period of the maize seeds was significantly shortened, the germination rate reached 92%, which was far higher than that of the bare soil. As an environment-friendly leather waste-based liquid film mulching, the WG could not only meet the growth of maize, increase yield, but also provide new ideas for the recycling of leather waste.